Hello,lately I have been reviving low frame rates in almost all of my games besides a few exceptions.
Here are my system specs;
Intel i5 750 @ 2.67
HIS ATI HD5870 1GIG
Cooler Master Elite 310 Red
WD ECO 1tb harddrive + WD 250G
Updated with all current drives and tempatures seem to be normal...
I typically get around 30-100fps but I used to get around 130+
It sounds like you were playing without vsync before, check to make sure thats not being forced on from the driver, and also within the games you are playing.
The most likely culprit though is the 10.6 drivers. I noticed a large degrade in performance with these in TF2 & BFBC2 (not source but still) (along with a few people i talked to with a similar setup). My solution was rolling back to 10.3a, you could go to 10.4, or even 10.5. Performance is stellar now. I'll just wait for 10.7 before upgrading again.
I usually play at my native resolution of 1680x1050, I have my Vsync option to only be on if the application asked to, I will try rolling back to 1.05 and see if anything happens.
Edit: I could only find the 1.04 drivers since it was on my installation disk, I will test teamfortress 2 to see if theres an performance increase.
Edit2:I have gotten an major performance increase out of driver 1.04 almost 300fps in some areas on cp_badlands on my server... Thank you